The Pure Data (short Pd) project on SourceForge unifies the extensions (or externals) written for the Pure Data Graphical Computer Music System written by Miller Puckette with contributions from many others.

NOTE: FontForge has moved to fontforge.github.io, newer binaries and sources are available at github.com/fontforge.
FontForge allows you to edit outline and bitmap fonts. You may create new ones or modify old ones. It is also a format converter and can interconvert between PostScript (ascii & binary Type1, some Type3, some Type0), TrueType, OpenType (Type2), CID, SVG

A whole bunch of utilities for primitive manipulation of
graphic images. Wide array of converters
from one graphics format to another. E.g.
from g3 fax format to jpeg. Many basic graphics
editing tools such as magnifying and cropping.

GraphicsMagick provides a set of commandline tools and programming APIs for manipulating, editing, and converting raster and vector images. It is derived from ImageMagick, with the objective of providing better stability and performance than ImageMagick.

Takes standard printer output produced by a DOS application, and forwards it to a default or selected Windows printer. Converts code page, strips empty pages, supports BOX DRAWINGS chars. Works on all Windows platforms. Written in Borland DELPHI.